Mass Distribution and Comfort

This week I had an interesting experience with customization and its effect on comfort.

Recently when I purchased three new Pure Storm GTs I knew I'd want to mod them up a bit in weight and SW. So when the first two arrived I added lead under the grip, swapped in my favorite comfort grip, added the OG, and added some lead in the head. In stock form the PSGT is too light for me but provides lots of room to customize to something I really like.

Then the third frame arrived from TW (the original was warped and returned to TW). I was feeling lazy and decided to just add the head lead and swap grips but didn't add any lead under the grip. I'd do that later as part of my detailed matching process (handle lead is usually my last step in matching).

Last night I hit with the three frames and to my surprise the frame lacking any lead under the grip was the most comfortable. It felt more "springy" and cushioned. So, right there on the court, I stripped out the lead from one of the other frames. Voila! That frame too felt more springy and comfortable. The handle lead removed/missing from the two frames was probably close to 0.4 or 0.5 ounces.

For some reason removing the lead under the grip allowed the frame to flex more or at least transmit less shock. I have no idea why this would happen but it did. Perhaps the lower mass in the handle allowed the handle/throat to flex more on impact acting as a shock absorb-er?

I think if you would put the 0.5 ounce around the butt, it will flex even more. I once added 25 grams on the rackethead and about 30 grams in the butt of a 280 gram racket. It had an enormous dwelltime, but it wasn't very playable. But when I distributed the mass more along the handle, but with most of the weight at the butt, I found a nice balance of dwelltime and crispness.

I think if you would put the 0.5 ounce around the butt, it will flex even more. I once added 25 grams on the rackethead and about 30 grams in the butt of a 280 gram racket. It had an enormous dwelltime, but it wasn't very playable. But when I distributed the mass more along the handle, but with most of the weight at the butt, I found a nice balance of dwelltime and crispness.

This mass had been distributed along the handle rather than just the butt.

Last night in an experiment I added a few more grams to the head. Comfort increased again.

The results surprised me too Povl. I guess not all added weight is created equal.

It makes sense though when one considers the fact that SW as "officially" calculated isn't really accurate. SW calculations assume the point of rotation is the near the wrist on the handle. That's fine if you're playing table tennis with your racquet and you're looking for a sore arm.

In reality the point of rotation is beyond the butt as pointed out by a book on the physics of tennis and available from TW. Actual SW is much greater than the official calculation and, contrary to the official calculation, weight under the grip DOES increase SW. For example, in tweaking my PSGTs this week and dropping the weight under the grip I was able to add weight in the head. It wasn't nearly a 1:1 ratio since weight in the head does effect SW more than that under the grip. But it was nice to get even more oomph in this frame while maintaining excellent RHS with a 6 point HL balance.

Since the actual point of rotation is behind the butt maybe mass under the grip prevents the frame from flexing more than it could than if weight is concentrated more in the head?

The increase in the swingweight felt when adding weight on the handle is true I believe, because you're swinging from a different axis indeed. I think because your mass was distributed along the handle, there was probably enough above your hand to make it feel stiffer.

Would you like to try adding the mass to the butt and tell what you think of it? If it increases comfort or not?